The air outlet of a ventilating system is often opened and closed by a series of vanes. The vanes are interconnected so that they move in unison. One of the vanes usually has a knob which can be used to adjust the vanes and control the volume and/or the direction of air flowing from the outlet.
Heretofore, in accordance with one approach, the knob has been formed as an integral part of the vane. The knob is plated with chrome or a similar bright, shiny material. The vane with the chrome-plated knob is then placed in a mold in which an overmold of rubber or similar elastomeric material is applied over the entire outer surface of the chrome-plated knob except for a narrow area which is not rubber-overmolded and hence is exposed to view. The rubber-overmold provides a friction surface enabling the vane to be adjusted easily by a thumb or finger of a vehicle occupant, and the exposed portion of the chrome-plate gives the knob an attractive appearance.
One problem with this procedure is that when overmolding the rubber on the chrome-plated knob, an edge of the mold cavity which contacts the chrome around the exposed area can make scratch marks on the chrome.
Alternatively, the vane and knob have been formed separately, with the knob inserted in a preformed hole in the vane. The two parts may be attached by a heat stake or a simple snap fit, but either way, the attachment is visible when the vane is tilted upwardly. These alternative methods involve additional machining costs as well as additional time and labor.